The present invention relates to a new circuit arrangement for monitoring the operation of an electronic yarn clearer mounted on an automatic yarn winding machine which comprises at least one winding station and at least one automatic knotting device, and is equipped with means for stopping the winding operation when the yarn breaks or is cut by intervention of the electronic yarn clearer, and means for actuating said automatic knotting device in this event. One such well known automatic yarn winding machine is the "Autoconer" manufactured by the firm W. Schlafhorst & Co, Moenchengladbach, West Germany.
Generally such an electronic yarn clearer comprises a device for sensing a transverse dimension, e.g. the diameter, of the traveling yarn, an electronic circuit serially connected to said sensing means and provided with a first output stage for generating cutting pulses due to incorrect yarn transverse dimension, and a second output stage for generating continuous signals indicative of yarn travel, or failure of yarn or yarn travel. It is known in the art to use the output signals of said output stages for controlling the winding and knotting operations mentioned above.
Now in factories equipped with a multiplicity of such automatic yarn winding machines and often comprising hundreds or even thousands of yarn winding units or stations it is an essential requirement to povide for automatic monitoring and protecting the electronic yarn clearers cooperating with the winding stations.
So-called primary events or deficiencies, as failure of a yarn sensing device or breakdown of the supply voltage of the electronic yarn clearer may be monitored without difficulty. Such primary events are characterized by the absence of electrical signals, such as the yarn sensing signals or supply voltages in the electronic circuitry of the yarn clearer, and may be detected for triggering an alarm by usual electric or electronic means.
However, it is not possible to protect and monitor the output mechanisms or members of an electronic yarn clearer by such known electric or electronic means.